public class Example4_5 {
    public static void main(String args[]) {
      Rect ractangle = new Rect ();
      ractangle.width=109.87;
      ractangle.height=25.18;
      double area =ractangle.getArea();
      System.out.println("矩形的面积:"+area);
      Lader lader = new Lader();
      lader.above=10.798;
      lader.bottom=156.65;
      lader.height=18.12;
      area = lader.getArea();
      System.out.println("梯形的面积:"+area);
    }
}

